UNIVERSITY    OF  CALIFORNIA    PUBLICATIONS. 

COLLEGE  OF  AGRICULTURE. 

AGRICULTURAL  EXPERIMENT  STATION, 

BERKELEY,  CALIFORNIA. 


THE 


CALIFORNIA  GRAPE  ROOT-WORM, 


By    H.  J.  QUAYLE. 


^b\ 


BULLETIN    No.    195 

(Berkeley,  Cal.,  July,  1908.) 


W.    \V.    SHANNON. 


SACRAMENTO: 

:     :     :     superintendent  state  printing. 
1908. 


AMIN  IDE  WHEELER,   Ph.D.,   LL.D.,  President  of  the   University. 


EXPERIMENT  STATION  STAFF. 

E.   J.   WICKSON,   M.A.,  Director  and  Horticulturist. 

E.   W.  HILGARD.   Ph.D.,  LL.D.,   Chemist. 

W.   A.   SETCHELL.   Ph.D.,   Botanist. 

ELWOOD  MEAD.  M.S..   C.E..  Irrigation  Engineer.      (Absent  on  leave.) 

LEROY  ANDERSON.  Ph.D.,  Dairy  Industry  and  Superintendent  University  .Farm. 

M.  E.  JAFFA.  M.S..  Nutrition  Expert,  in  charge  of  the  Poultry  Station. 

C.  W.  WOODWORTH,  M.S.,  Entomologist. 

R.  H.  LOUGHRIDGE.  Ph.D.,  Soil  Chemist  and  Physicist. 

G.  W.   SHAW,  M.A.,   Ph.D.,  Agricultural  Technologist,  in  charge  of  Cereal  Stations. 

GEORGE  E.   COLBY,  M.S.,   Chemist.      (Fruits,   Waters,  Insecticides.) 

RALPH  E.  SMITH,  B.S.,  Plant  Pathologist  and  Superintendent  of  Southern  California 

Pathological  Laboratory  and  Experiment  Station.      Whittier. 
A.   R.   WARD,    B.S.A.,   D.V.M.,   Veterinarian  and  Bacteriologist. 
E.   W.   MAJOR,  B.Agr.,  Animal  Industry. 
H.  M.  HALL.  M.S.,  Assistant  Botanist. 
H.  J.  QUAYLE.  A.B.,  Assistant  Entomologist.     Whittier. 
W.    T.    CLARKE,    B.S.,    Assistant    Horticulturist    and    Superintendent    of    University 

Extension  in  Agriculture. 
JOHN  S.  BURD,  B.S.,  Chemist,  in  charge  of  Fertilizer  Control. 
C.  M.  HARING,  D.V.M.,  Assistant  Veterinarian  and  Bacteriologist. 
H.  A.  HOPPER,  B.S.A.,  Assistant  in  Dairy  Husbandry. 
J.  H.  NORTON,  M.S.,  Assistant  Chemist  in  charge  Fertilizer  ) 

Experiments,  I       Citrus  Experiment 

HUNT,  B.S.,  Assistant  Horticulturist,  )  Station,  Riverside. 

BABCOCK,  B.S.,  Assistant  Plant  Pathologist. 
SMITH,  M.S.,  Assistant  Plant  Pathologist. 
YEAW,  B.S.,  Assistant  Plant  Pathologist. 

RAMSEY,  M.S.,  Assistant  Plant  Pathologist,  )        Southern  California  Patholog- 
SMITH,   M.S.,  "  "  "  f  ical  Laboratory.     Whittier. 

MANSELL,  Assistant  in  Horticulture,  in  charge  of  Central  Station  Grounds. 
RALPH   BENTON,   B.S.,   B.L.,  Assistant  in  Entomology. 
A.  J.  GAUMNITZ,  M.S.,  Assistant  in  Cereal  Investigations. 
RACHAEL  CORR,  M.A.,  Assistant  in  Cereal  Laboratory. 
HANS  C.   HOLM,  B.S.,  Assistant  in  Zymology. 

P.  L.  McCREARY,  B.S.,  Laboratory  Assistant  in  Fertilizer  Control. 
F.  E.  JOHNSON,  B.  L.,  Assistant  in  Soil  Laboratory. 
M.   E.   STOVER,  B.S.,  Assistant  in  Agricultural  Chemical  Laboratory. 

D.  R.   HOAGLAND,  A.B.,   Assistant  in  Agricultural  Chemical  Laboratory. 
CHARLES  FUCHS,  Curator  Entomological  Museum. 

P.  L.   HIBBARD,  B.S.,  Assistant  Fertilizer  Control  Laboratory. 

M.  E.  S  HER  WIN,  Field  Assistant  in  Agronomy. 

W.  H.  VOLCK,  Field  Assistant  in  Entomology.     Watsonville. 

E.  L.  MORRIS,  B.S.,  Field  Assistant  in  Entomology.     San  Jose. 
J.  S.  HUNTER,  Field  Assistant  in  Entomology.     San  Mateo. 

D.   L.  BUNNELL,  Clerk  to  the  Director. 


T. 

F. 

E. 

E. 

E. 

EL 

F. 

L. 

H. 

J. 

C. 

o. 

R. 

e. 

Patron,  ,  Tulare  substation,   Tulare. 

J.   T.   BEAK.-.-,   Foreman,      * 

'        '     "    '    ^./     r       7   '  University  Forestry  Station,  Chico. 

E    (     MILLER,  In  charge,    )  J 

ROT  JONES    Patron,  I  University  Forestry  Station,  Santa  Monica. 

(HAM,   Foreman,    f 

T     J.     HUNTLEY,     Foreman     of     California     Poultry     Experiment     Station, 
Pi  tain  ■ 

The  Station  publications  (Reports  and  Bulletins),  so  long  as  avail- 
able, will  ho  sent  to  any  citizen  of  the  State  on  application. 


THE  CALIFORNIA  GRAPE  ROOT-WORM. 

(Adoxus  obscurus  Linn.) 
By  H.  J.  QUAYLE. 


The  California  Grape  Root-worm  is  an  insect  that  attacks  both  the 
roots  and  the  growing  parts  of  the  vine  above  ground.  It  has  been 
known  to  attack  the  leaves  of  the  vine  in  this  State  for  a  good  many 
years,  but  until  a  year  or  two  ago  it  was  unknown  as  a  root  feeder.  It  is 
similar  in  its  life  history  and  mode  of  attack  to  the  well-known  grape 
root- worm  of  the  Eastern  States,  which  is  one  of  the  worst  pests  that  the 
vineyardists  there  have  to  wage  war  against.  Our  species  has  been  doing 
considerable  damage  during  the  past  two  or  three  years,  and  it  promises 
to  be  an  important  enemy  of  the  vine  in  California. 

Early  History  in  Europe. — The  first  account  of  this  insect,  which 
leaves  little  doubt  as  to  its  identity,  was  given  by  Aldrovandi  in  1602.1 
It  is  one  of  the  important  pests  of  the  vine  in  France,  as  is  shown 
by  the  amount  of  literature  on  the  insect  that  has  appeared  in  that 
country.  Pluchi2  in  1732  stated  that  it  passed  the  winter  in  the  ground, 
and  this  is  the  first  suggestion  we  have  of  its  underground  habits, 
although  it  was  not  actually  known  by  this  author  to  feed  upon  the 
roots.  The  first  authentic  observation  on  the  root-feeding  habits  appears 
to  have  been  made  in  1849  by  Demermety,3  who  found  it  feeding  upon 
the  roots  of  vines  in  France. 

It  has  received  rather  careful  attention  from  a  number  of  observers 
in  Europe,  but  probably  the  most  complete  account  is  given  in  Mayet's 
"Insectes  de  la  Vigne."  It  also  occurs,  as  a  grape  pest,  in  Germany, 
Italy,  and  Algeria,  as  well  as  in  France. 

In  California. — The  first  account  of  this  insect  occurring  on  vines  in 
California,  so  far  as  we  have  been  able  to  find,  is  a  brief  notice  in  the 
"Pacific  Rural  Press"  for  May  29,  1880.  It  is  here  stated  that  "every 
spring  for  the  last  few  years  there  have  been  received  specimens  of  a 
dark  colored  beetle  about  one  fifth  of  an  inch  long  which  eats  the  leaves 
of  the  grapevine  until  almost  skeletonized."  It  is  doubtful  from  this 
account  just  what  beetle  is  referred  to,  but  the  description  of  the  beetle 
and  its  work  on  the  leaves,  and  the  time  of  the  year  of  its  occurrence, 

1  Des  Insectes,  p.  472. 

2  Spectacle  de  la  Nature ;  Paris. 

3  Jour.  d'Agr.  de  Dijon. 


I  UNIVERSITY  OF  CALIFORNIA — EXPERIMENT  STATION. 

-  ggests  the  root  beetle.  Moreover,  Professor  Wickson  who  was  horti- 
cultural editor  of  the  "Press"  at  the  time,  remembers  that  the  article 
had  reference  to  this  species  as  we  now  know  it,  and  not  to  the  fiea-beetle 
with  which  it  has  been  commonly  confused. 

The  first  full  account  of  its  occurrence  in  this  State  appears  in  an 
article  by  Matthew  Cooke1  in  1883.  He  confuses  it  with  the  flea-beetle, 
but  he  gives  it  the  scientific  name  of  Adoxus  vitis,  and  from  his  account 
there  is  no  mistaking  the  insect  to  which  he  refers.  He  states  that 
"it  was  reported  from  at  least  six  of  the  vine-growing'  sections  of  the 
State  in  1882.  and  in  1883  was  destroying  the  vines  infested.  One 
vineyard  in  the  vicinity  of  Sacramento  was  damaged  seriously  that 
spring.  Its  mode  of  attack  is  similar  to  that  of  the  steel-blue  fiea- 
beetle  (Haltica  chalybea  111.),  and  it  frequently  damages  young  vines 
to  such  an  extent  that  they  die.  It  is  an  insect  enemy  of  the  vine  that 
must  be  eradicated." 

There  is  nothing  said  about  the  life  history  in  this  account,  except 
that  it  attacks  the  vine  in  the  same  way  as  the  flea-beetle.  It  is  also 
given  the  common  name  of  "Imported  Grape  Flea-beetle,"  and  we 
therefore  infer  that  he  knew  nothing  of  its  attacking  the  roots.  Neither 
is  there  anything  in  the  literature  of  the  State  which  has  appeared 
since  that  would  indicate  that  it  is  a  root  feeder. 

Its  economic  status  as  given  by  Cooke  was  based  entirely  on  the 
damage  done  to  the  leaves.  Important  as  that  is,  it  is  really  of  much 
Jess  consequence  than  the  attack  on  the  roots,  as  is  now  known  to  be 
the  case.  Accounts  of  injury  by  this  beetle  have  appeared  from  time 
to  time  since  in  the  press  of  the  State.  Alexander  Craw2  then  State 
quarantine  officer,  gave  a  short  account  of  the  beetle  in  1897.  He 
described  its  attack  on  the  leaves,  and  figured  a  leaf  showing  the  char- 
ristic  work  of  the  beetle,  but  was  apparently  unaware  of  its  under- 
ind  habits. 

Riley  and  Howard3  in   1891  stated  that  "In  Europe  Adoxus  vitis 

is  injurious  to  the  grape,  the  larvae  feeding  on  the  roots  and  the  beetle 

destroying  the  leaves,  whereas  in  America  it  is  only  known  to  attack 

a  wild  plant   (Epilobium).     Mr.  E.  Dupont  has  recently  investigated 

subject  of  oviposition  and  finds  that  it  occurs  only  on  the  foliage, 

the  young  larva  afterwards  entering  the  ground.     The  life  history  of 

Adoxus  is  thus  in  conformity  with  that  of  an  allied  species,  Chryso- 

auratus  which  lives  on  Apocynum  and  rosoemi folium.     We  have 

found  the  eggs  on  the  leaves  and  the  larvae  underground  feeding  on 

The   Dearest   North   American   allies  of  Adoxus,   viz.,  the 

of  Pidia,  also  infest  the  grapevine,  but  their  life  histories  have 

3  In.;.  In  ectfi   of  the  Orchard  and   Vineyard,  1883. 

j  Destrud  ive  Insects,  1897. 
insect  Life,  vol  III,  p.  349. 


Bulletin  195.  CALIFORNIA  GRAPE  ROOT-WORM.  3 

never  been  investigated. ' '  The  first  actual  observation  on  the  root-feed- 
ing habits  on  the  grape  in  this  country,  so  far  as  we  know,  was  made 
by  Mr.  0.  Butler  of  this  station,  who  found  it  on  the  roots  of  vines  near 
Lodi  in  1905. 

Its  Name. — A  beetle  was  described  in  1602  by  Aldrovandi,1  which 
seems  to  answer  the  description  of  this  species ;  but  it  was  placed  in 
the  wrong  group  by  this  author,  and  it  was  also  before  the  adoption 
of  the  binomial  system  of  nomenclature.  It  has  been  described  under 
two  or  three  different  generic  names  since,  but  the  one  now  adopted  is 
Adoxus,  given  by  Kirby  in  1837. 

Linnaeus  in  1741  described  a  beetle,  to  which  he  gtive  the  specific 
name  obscurus.  This  is  now  known  as  Adoxus  obscurus,  and  is  the 
name  that  has  been  applied  to  the  black  form  of  the  beetle  occurring 
in  California  and  elsewhere  in  the  United  States.  Mayet2  states  that 
obscurus  Linn,  is  somewhat  larger  than  vitis,  entirely  black,  and  found 
on  a  plant  (Epilobium)  of  the  marshy  prairies,  sometimes  upon  "trifli" 
clover,  Tjut  never  on  the  vine.  Dr.  Horn3  states  that  the  only  known 
species  of  the  genus  inhabits  Europe  and  the  northern  part  of  our  own 
continent,  and  that  it  varies  in  a  similar  manner  in  both  regions. 

In  California  it  is  certain  that  both  the  black  and  brown  forms  are 
the  same  species.  Wherever  the  beetle  was  seen  during  the  past  two 
years  the  two  forms  occurred  in  about  equal  numbers,  and  were  found 
interbreeding  in  all  combinations.  A  large  number  of  specimens  of  A. 
vitis  were  kindly  sent  to  us  by  Professor  Valery  Mayet  of  Montpellier, 
France,  and  they  appeared  to  be  identical  with  the  brown  form  occur- 
ring here.  He  also  sent  us  two  specimens  of  A.  obscurus,  saying  that 
these  were  very  rare  and  never  found  on  the  vine,  as- noted  above.  They 
were  slightly  larger  than  the  black  form  occurring  on  the  vine  here. 

On  account  of  the  great  difference  in  food  plants  it  would  appear 
that  the  obscurus  of  France  is  a  distinct  species  from  that  of  vitis;  but 
an  inquiry  into  the  geographical  distribution  of  the  two  forms  seems  to 
indicate  that  it  is  simply  a  case  of  a  dichromatic  species,  with  one  or  the 
other  of  the  two  forms  predominating  in  the  different  regions,  with  the 
exception  of  the  California  vineyards,  where  both  forms  occur  in  about 
equal  numbers. 

On  account  of  priority  the  correct  specific  name  should  be  obscurus 
Linn,  representing  the  black  form,  while  vitis  F.  should  be  applied  to  the 
bi colored  variety. 

In  France  this  insect  goes  by  the  common  name  of  Le  Gribouri  or 
Ecrivain,  the   scrawler  or  writer;  but  since  these  names  are  hardly 

1  Des   Insectes,   1602. 

2  Insectes  de  la  Vigne,  p.  322,  1S90. 
3Amer.    Entomol.    Soc,    vol.    19,    p.    196. 


4  UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 

applicable  in  this  country  and  because  of  the  possible  confusion  with 
the  engraver  beetles,  it  docs  not  seem  desirable  to  adopt  either  of  these 
as  a  common  name  for  the  insect.  Cooke  gave  it  the  name  of  "Imported 
Grape  Flea-beetle";  but  since  it  is  not  a  flea-beetle  at  all,  this  name  is 
not  warranted.  Since  the  life  history  and  habits  of  this  species  are 
almost  identical  with  those  of  the  Grape  Root-worm  (Fidia  viticida 
Walsh]  of  the  Eastern  States,  and  the  fact  that  it  is,  thus  far  at  least, 
a  grape  pest  in  this  country  only  in  California,  we  have  given  it  the 
common  name  of  California  Grape  Root-worm. 

Distribution. — According  to  Dr.  Horn1  the  obscurus  or  black  form 
occurs  most  abundantly  in  California  and  Nevada  and  one  specimen  has 
been  noted  from  Colorado.  The  vitis  form  extends  from  New  Hamp- 
shire westward  to  the  Lake  Superior  region,  Utah,  Colorado,  and  Wash- 
ington, only  a  few  specimens  coming  from  the  last  three  localities. 
Dr.  Hamilton  in  his  catalogue  mentions  Adoxus  vitis  as  "widely  dis- 
tributed across  the  northern  part  of  the  continent,  extending  north 
on  Mount  Washington,  N.  H.,  to  the  Hudson  Bay  region,  westward  to 
California  and  south  to  New  Mexico ;  and  southward  in  the  Atlantic 
States  through  New  York."  A.  L.  Melander,  entomologist  of  the 
Washington  Station,  states  that  there  is  but  a  single  specimen  in  their 
collection  taken  in  the  Grand  Coulee  in  1892.  Professor  Cordley  of  the 
Oregon  Station  writes  that  he  has  no  record  of  its  occurring  in  that 
state  on  the  grape,  nor  has  Professor  Alclrich  any  record  of  its  occur- 
rence in  Idaho. 

Through  the  kindness  of  A.  L.  Quaintance  of  the  Bureau  of  Ento- 
mology, Washington,  we  are  able  to  give  the  localities  of  obscurus  and 
vitis  occurring  in  the  National  Museum  Collection,  as  follows:  Mount 
Adams  and  Mount  Washington,  N.  H. ;  Marquette  and  Port  Huron, 
Mich. ;  numerous  specimens  from  New  York  and  New  Jersey ;  Isle 
Ptoyal  and  Michipicoten  Bay,  Lake  Superior;  Colorado  Springs, 
Yeta  Pass,  Elk  Park,  and  Garland,  Colorado ;  Bear  Paw  Mountain, 
Mont. ;  Park  City  and  Alta,  Utah ;  Kaslo  and  Bear  Lake,  B.  C. ;  Easton, 
Washington;   Portland,   Oregon;   Placer,   Alameda,   Los  Angeles,   and 

-ma,  California;  and  Bulah,  New  Mexico. 

We  are  indebted  to  Dr.  E.  C.  Van  Dyke,  of  the  California  Academy 

of  Sciences,  for  some  interesting  facts  on  the  distribution  of  Adoxus, 

from  whom  we  quote  as  follows:  "The  various  species  of  its  native 

food  plant,  Epilobium,  is  widely  distributed  over  the  northern  parts  of 

>pe,  Asia  and  North  America.     On  the  Pacific  Slope  the  beetle  is 

found  in  all  of  the  lowlands  of  western  Washington  and  the  northern 

hair  of  western   Oregon  and  extends  south  along  the  Cascades   (here 

to  near  the  timber  line,  some  specimens  being  taken  at  an  elevation 

i  000  feet  on  the  snow  fields  of  Mount  Rainier)  ;  along  the  Sierras  to 
~^T;  t.  Entomol.  Soc,  XIX,  p.  198,  1892. 


Bulletin  195.  CALIFORNIA  GRAPE  ROOT-WORM.  5 

at  least  as  far  south  as  Tulare  County,  California.  This  region,  includ- 
ing also  the  Eastern  States,  with  the  exception  of  the  Sierras  in  Cali- 
fornia, is  occupied  by  the  bicolored  variety  vitis  F.  The  melanotic  form 
or  true  obscurus  L.  has  been  found  besides  in  California,  in  Colorado, 
and  one  specimen,  among  many  thousands  of  the  variety  vitis  F.,  at  Port 
Angeles,  Washington. 

"The  insect  is  found  throughout  Siberia,  where  in  the  Amoor  region 
and  around  Lake  Baikal,  the  true  obscurus  L. — according  to  the  cata- 
logue of  L.  Von  Heyden,  which  clearly  differentiates  the  two  forms — 
is  the  dominant  one,  and  perhaps  as  much  a  race  there  as  it  is  here. 
In  west  Siberia  the  variety  vitis  F.  seems  to  be  the  predominant  one. 
This  peculiarity  of  distribution  is  in  keeping  with  that  of  many  of  the 
other  species  of  beetles  that  are  common  to  both  continents,  the  eastern 
specimens  related  to  the  more  western  of  those  of  the  old  world,  while 
ours  are  more  closely  related  to  those  of  the  highlands  of  southeastern 
Siberia,  etc.,  the  so-called  Japano-Manchurian  region." 

It  appears  then  that  the  obscurus  form  living  upon  its  native  food 
plant  in  the  Sierra  Nevada  mountains  has  transferred  itself  to  the  vine- 
yards, but  here  instead  of  obscurus  occurring  exclusively,  both  obscurus 
and  vitis  occur  in  about  equal  numbers.  The  points  at  which  the  beetles 
were  reported  as  injurious  this  year  from  Merced  to  Marysville,  parallel 
with  the  Sierras,  points  strongly  to  the  fact  that  it  has  come  down  from 
the  mountains  and  established  itself  in  the  vineyards  of  the  valley. 
The  beetles  also  occur  in  the  Sonoma  Valley,  and  this  may  be  accounted 
for  by  the  fact  that  its  native  food  plant  is  also  found  here.  According 
to  Jepson,1  the  fire  weed  (Epilobium  spicatum)  has  been  collected  in 
western  and  middle  California  only  in  Sonoma  County,  near  Guerne- 
ville.  The  distribution  of  this  insect,  with  its  varying  color  forms  in  the 
different  regions  and  its  apparent  transfer  to  cultivated  plants,  present 
an  interesting  biological  problem. 

As  an  economic  species  it  is  widely  distributed  in  Europe,  occurring 
particularly  in  the  vineyard  sections  of  France,  Italy,  and  Algeria. 
Here  in  the  United  States  it  seems  to  have  gained  its  strongest  foothold 
in  California.  According  to  Cooke  it  was  reported  from  six  of  the 
principal  grape  sections  of  the  State  as  far  back  as  1882.  Within  the 
last  two  or  three  years  it  has  been  most  abundant  in  the  Sacramento  and 
San  Joaquin  valleys,  and  in  the  coast  region  near  Sebastopol  and 
Healdsburg. 

Related  Species. — In  the  Eastern  States,  particularly  in  the  grape 
growing  sections  of  Ohio  and  the  Chautauqua  belt  of  New  York,  there 
is  a  similar  insect  called  the  grape  root-worm  (Fidia  viticida  Walsh) 
that  does  very  serious  injury  to  the  vineyards.     This  insect  has  been 

1  Flora  of  Western  and  Middle  California,  p.  329. 


0  UNIVERSITY    OF   CALIFORNIA— EXPERIMENT   STATION. 

known  to  occur  in  New  York  since  1866,  and  has  been  a  pest  on  the  vines 
there  since  about  1893. 

This  insect  in  all  essential  respects,  so  far  as  habits  go,  is  similar  to 

the  one  treated  of  in  this  bulletin.     It  is  also  closely  related  entomolog- 

ieally.  both  being  members  of  the  same  group  (Emolpini) .    The  common 

brotica,  the  flea-beetles,  the  asparagus  beetle,  and  numerous  other 

leaf  eating  beetles  belong  to  this  same  family. 

Economic  Importance. — While  the  insect  has  occurred  on  vines  in  the 
State  for  the  last  thirty  years  it  seems  not  to  have  spread  so  rapidly  as 
might  have  been  expected,  judging  from  the  experience  with  the  same 
insect  in  Europe  and  its  related  species  in  the  Eastern  States.  It  is 
difficult  to  explain  just  what  may  account  for  this. 

Since  the  greater  part  of  the  insect's  life  is  spent  in  the  ground,  it  is 
in  this  stage  that  conditions  would  be  most  likely  to  influence  its 
progress.  Such  conditions  might  be  found  in  the  kind  of  soil,  the 
cultivation  of  the  soil,  the  variety  of  vines  and  the  great  depth  of  the 
root  systems  in  some  of  our  drier  sections.  Again,  the  true  importance 
of  the  insect's  work  has  never  been  appreciated  in  the  State  hitherto, 
since  it  has  been  known  as  a  leaf  feeder  entirely.  Vines,  therefore,  may 
have  shown  a  general  unthriftiness  due  to  its  attacks,  but  because  the 
root  infesting  habits  of  the  larvas  were  unknown  the  trouble  may  have 
been  assigned  to  other  causes. 

However,  during  the  present  season  in  the  neighborhood  of  Lodi, 
we  have  good  evidence  of  what  injury  the  insect  may  bring  about.  In 
the  particular  vineyard  where  our  studies  were  made,  it  had  been 
noticed  that  something  was  wrong  with  the  vines,  but  just  wrhat  it  was 
had  not  been  determined.  During  the  past  winter  two  or  three  acres 
of  the  vines  which  were  worst  affected  were  dug  up.  The  piece  adjoin- 
ing where  the.se  vines  were  uprooted  was  badly  infested  during  the 
past  spring  with  a  beetle  with  which  the  owner  (who  came  into  posses- 
sion of  the  property  a  year  ago)  was  unfamiliar.  The  matter  was 
reported  to  us  and  upon  investigations  it  was  found  to  be  the  root  beetle. 

The  beetles  were  very  abundant  over  a  narrow  strip  in  the  center  of 

vineyard  and  had  already  done  considerable  injury  to  the  leaves 

and  other  growing  pari  3  of  the  vines.    The  men  who  pruned  the  vineyard 

in  the  winter  noticed  that  this  strip  of  vines  had  not  made  the  growth 

that  was  made  by  the  vh  es  on  either  side.    Fortunately  the  old  stumps 

}ijf}j  had  been  dug  up  had  been  saved  for  fuel,  and  upon 

were  found  to  be  badly  gnawed  by  this  insect.     Some  of 

the  vines  in  the  strip  where  the  beetles  were  abundant  this  year  made 

practically  do  growth  until  Late  in  the  season.    The  beetles  were  nearly 

al]  killed  on  this  area  Hi  is  year,  and  hence  the  vines  became  free  from 

the  larvae  and  started  their  growth  very  late.     On  another  vineyard 


Bulletin  195.  CALIFORNIA  GRAPE  ROOT-WORM.  7 

near  Lodi  these  beetles  have  been  very  numerous  for  two  or  three  years, 
and  the  owner  estimated  that  his  crop  had  been  reduced  from  one  third 
to  one  half.  These  two  instances  are  comparable  with  what  has  occurred 
over  a  considerable  area  in  the  Eastern  States  on  account  of  the  presence 
of  the  other  species  there. 

Our  species  has  been  observed  in  several  vineyards,  and  doing  consid- 
erable damage  in  1908  where  they  were  not  seen  at  all  in  1907.  This 
may  be  partly  accounted  for  through  the  excessive  rain  in  the  spring 
of  1907  causing  their  temporary  disappearance,  but  there  is  no  doubt 
that  the  insect  is  becoming  more  widely  distributed.  The  station  has 
also  received  more  inquiries  about  the  insect  than  usual  during  the 
season  just  passed. 

The  attacks  of  this  beetle  have  been  credited  with  being  the  cause  of 
the  sunburn  of  the  Tokay  grape.  The  theory  of  those  who  support 
this  view  is  that  the  gnawing  of  the  beetles  on  the  stalks,  pedicels  and 
berries  "poisons  the  sap"  or  injures  the  bunch  mechanically,  and  thus 
induces  the  drying  and  shriveling  of  the  berries. 

The  experiments  and  observations  of  Messrs.  0.  Butler  and  B.  J. 
Wingfield,  at  Florin  in  1905,  indicate  that  the  above-ground  attacks 
of  the  beetle  have  little  or  nothing  to  do  with  causing  sunburn  unless, 
of  course,  there  is  more  or  less  actual  defoliation.  Besides  exposure, 
sunburn  seems  to  be  due  to  several  causes,  tending  to  diminish  the 
vigor  of  the  vine,  and  probably  the  underground  attacks  of  the  beetle 
larvas  are  among  the  most  serious  of  these  weakening  causes. 

The  Soil  It  Infests. — The  typical  soil  in  the  Tokay  grape  section  about 
Lodi  is  a  sandy  loam.  It  is  in  such  soil  that  the  vineyards  mentioned 
above  are  located.  In  another  vineyard,  however,  near  Stockton,  beetles 
were  present  in  considerable  numbers  in  the  black  adobe  soil  character- 
istic of  that  region.  About  Florin,  where  the  soil  is  clayey,  the  insect  is 
also  troublesome. 

Dr.  Felt1  in  speaking  of  the  eastern  root-worm's  .preference  for  soil 
says:  "The  depredations  of  this  pest  are  much  worse  and  usually  first 
apparent  in  light,  sandy  or  poor  soils,  and  in,  particular  on  gravelly 
knolls.  The  insects  seem  to  thrive  under  such  conditions  and  a  defi- 
cient growth  should  lead  to  immediate  investigation.  Vines  on  rich 
clay  soils  in  our  experience  sustain  comparatively  little  injury  from  this 
pest,  and  this  appears  to  be  the  case  in  Ohio. ' ' 

Preference  for  Varieties. — With  a  view  to  determining  whether 
or  not  seme  varieties  are  resistant  to  the  attacks  of  the  eastern  species, 
the  Cornell  Experiment  Station  secured  roots  of  several  types  of  Ameri- 
can vines,  and  after  grafting  them  on  to  the  standard  varieties  grown 
there,  distributed  them  in  the  infested  districts.  The  work  is  still  in 
the  experimental  stage,  but  it  may  be  promising  as  a  line  of  possible 


New  York  State  Museum  Bulletin  59. 


8  UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

control  for  such  a  root  infesting-  insect.  In  the  same  bulletin  it  is 
stated  that  some  large  vines  of  a  "native  type"  growing  along  a  fence 
within  a  few  feet  of  a  badly  infested  Concord  vineyard  suffered  no 
injury,  not  even  the  leaves  being  eaten  by  the  beetles. 

Our  own  observations  on  the  matter  of  resistant  varieties  for  the  root- 
worm  in  California  have  not  been  extensive  enough  to  warrant  drawing 
any  conclusions.  The  infested  vineyards  at  Lodi  are  of  the  Tokay  and 
Zinfandel  varieties,  but  since  these  are  the  principal  grapes  grown 
here,  it  proves  nothing.  In  other  sections  many  different  varieties  of 
vines  are  subject  to  attacks  by  this  insect. 

APPEARANCE  AND  DESCRIPTION  OF  THE  STAGES. 

The  Egg. — The  eggs  of  this  beetle  are  small  yellowish  white  objects 


Fig.  1.     A  cluster  of  eggs  as  they  are  found  naturally  on  the  Fig.  2.     A  single  egg  highly 

bark  (enlarged).  magnified. 

which  may  be  found  in  clusters  (Fig.  1)  under  the  old  bark  of  the  vine. 
An  individual  egg  (Fig.  2)  is  about  one  twenty-fifth  of  an  inch  long 
and  somewhat  cylindrical  in  shape,  being  about  one  third  as  broad  as 
long. 

The  Larva. — The  full  grown  larvge  vary  considerably  in  size,  but 
the  larger  number  will  measure  a  little  more  than  a  quarter  of  an  inch, 
as  they  are  found  naturally  in  a  slightly  curved  position.  When  they 
are  straightened  out  they  measure  seven  twentieths  to  eight  twentieths 
of  an  inch.  They  are  white  in  color,  excepting  the  head,  which  is  yellow- 
ish brown,  with  the  mouth  parts  dark  brown  or  black.  The  arrangement 
of  hairs  is  as  shown  in  figure  3.    The  spiracles  are  indicated  by  a  yellow- 


Bulletin  195. 


CALIFORNIA   GRAPE   ROOT-WORM. 


ish  spot  or  ring  and  are  easily  visible.  The  proximal  joint  of  the  labial 
palpus  is  as  long  as  the  other  four.  The  antennas  are  short  and  incon- 
spicuous, consisting 
of  three  joints  and 
ending  in  a  couple  of 
peg-like  processes  and 
two  small  spines.  The 
legs  are  covered  with 
hairs  or  setae  similar 
to  those  on  the  body. 
The  claws  are  long, 
slightly  curved,  and 
dark  brown  in  color. 

The  Pupa.  —  The 
pupa  (Figs.  4  and  5) 
is  about  one  fourth  of  an  inch  long  and  about  the  same  length  across  the 
extended  wing  pads.  The  color  is  pure  white,  the  hairs  or  spines  alone 
being  colored  brown.  On  the  head  near  the  prothorax,  extending  trans- 
versely, is  a  row  of  four  spines,  and  behind  this  row  are  four  spines, 
slightly  smaller,  arranged  in  the  form  of  a  quadrangle.     On  the  dorsal 

side  of  the  abdomen 

/Y    //v 


Fig.  3.     Larva. 


^ 


are  transverse  rows 
of  delicate  hairs.  The 
anterior  and  hind 
femora  are  armed 
with  a  stout  spine. 
On  the  hind  femora 
there  are  also  two 
stout  bristles.  The 
anal  hooks  are  very 
stout  and  broad  at 
the  base,  ending  in  a 
sharp  spine,  curved 
upward  and  tipped 
with  black.  Just 
anterior  to  the  anal 
hooks  on  the  dorsal 
side  is  a  row  of  four 
short  blunt  spine- 
like tubercles,  each 
ending  in  a  bristle.  On  the  next  anterior  segment  is  a  row  or  six  spines. 
These  are  longer  and  stouter  than  those  on  the  other  segment,  but  end 
in  a  similar  sharp  bristle.    There  are  two  pairs  arranged  on  either  side 


Fig.  4.     Pupa.    Dorsal  view. 


10 


UNIVERSITY    OF    CALIFORNIA-     EXPERIMENT    STATION. 


of  the  dorsal  line,  and 
There  are  also  hairs  or 


below  these  laterally  is  a  similar  single  spine. 

bristles  extending  farther  laterally. 

The  Beetle.— There 
are  two  forms  of 
the  adult  beetle  oc- 
curring in  the  State, 
one  being  black-  in 
color  and  the  other 
mostly  brown. 
There  is  consider- 
able difference  in 
the  size  of  different 
specimens,  and  par- 
ticularly in  the 
sexes  —  the  males 
being  much  smaller. 
On  an  average  they 
will  measure  about 
one  fifth  of  an  inch 
in  length. 

The  black  form 
(Adoxus       obscurus 


Fig.  5.      Pupa.    Ventral  view, 


/ 


ym^ 


Linn.)       is      almost 
wholly  black  in  color. 
The    antennae,    tibia 
and   tarsi,   however, 
in    some    specimens       / 
merge      into      dark 
brown.      The   entire 
body,  as  well  as  the 
appendages,  are  cov-  j 
ered  with   a   pubes- 1 
eence  of  short  gray 
hairs! 

The    brown    form 

[Adoxus  vitis  Fab.) 

tie  elytra,  tibia 

basal    half    of 

the  antennas  brown, 

while  the  remaining 

are  black.     It 

is    covered    with    a 

►ence  as  is  the  other  form.  The  head  in  both  is  capable  of 
being  well  retracted  inio  the  prothorax.  Both  forms  of  the  beetle  are 
about  equally  distributed,  and  interbred  indiscriminately. 


Fig.  c>.     Adult  of  the  grape  root-worm. 


Bulletin  195.  .   CALIFORNIA  GRAPE  ROOT-WORM.  11 

LIFE  HISTORY  AND  HABITS. 

The  Egg. — The  eggs  of  this  beetle  are  laid  usually  in  crevices  beneath 
the  inner  layers  of  bark  on  the  old  wood.  They  are  not  confined  to  last 
year's  wood,  as  seems  to  be  the  case  with  its  eastern  ally,  but  are  laid 
anywhere  on  the  stump  of  the  vine  above  four  or  five  inches  from  the 
ground.  With  the  California  system  of  pruning,  there  is  of  course 
little  of  last  year's  wood  left  on  the  vine,  and  the  bark  on  this  is  too 
smooth  to  offer  the  most  suitable  situations  for  egg  laying.  Indeed, 
during  the  past  season  we  found  no  eggs  on  last  year's  wood,  but  all 
on  the  older  part  of  the  stump,  which  was  covered  with  two  or  three 
layers  of  old  bark.  In  some  cases,  where  the  bark  was  in  close  contact 
with  the  wood,  it  was  hard  to  explain  how  the  beetle  got  beneath  the 
two  or  three  layers  to  deposit  its  eggs.  In  nearly  every  case  they  were 
certainly  well  protected  from  most  enemies  and  out  of  reach  of  any 
spray. 

The  eggs  are  laid  in  clusters  of  from  four  or  five  to  twenty-five  or 
thirty;  usually  where  the  smaller  numbers  were  found  the  crevice  in 
which  they  were  deposited  would  not  furnish  room  for  a  larger  number. 
Where  there  was  plenty  of  space  the  number  ranged  from  a  dozen  to 
thirty.  The  most  common  numbers  counted  in  the  many  clusters  exam- 
ined ranged  from  ten  to  twenty. 

The  eggs  in  the  cluster  may  be  irregularly  arranged  or  somewhat  in 
the  form  of  a  concentric  ring,  the  particular  arrangement  depending 
probably  upon  the  space  in  which  they  are  deposited.  Where  there  was 
plenty  of  room  the  eggs  were  sometimes  well  scattered,  extending  over 
a  diameter  of  a  quarter  of  an  inch  or  more.  In  other  cases  a  pretty 
well  defined  concentric  arrangement  was  found.  Occasionally,  a  small 
crevice  would  be  found  with  but  two  or  three  eggs. 

Number. — The  largest  number  we  succeeded  in  getting  a  single 
female  to  lay  in  our  breeding  cages  was  seventy-nine.  These  were  laid 
at  three  different  intervals,  extending  over  a  period  of  about  one  month. 
Others  laid  but  a  single  cluster  of  from  fourteen  to  twenty  and  then 
died.  The  same  insect  in  France,  according  to  Mayet,1  lays  in  the 
neighborhood  of  thirty  eggs  either  singly  or  in  patches  on  the  under 
side  of  the  leaves.  This  number  is  probably  simply  an  approximation. 
The  fact,  if  it  is  a  common  occurrence,  that  they  are  laid  on  the  under 
side  of  the  leaves,  is  the  most  striking  difference  between  the  habits 
in  California  and  in  France.  We  have  had  some  eggs  laid  on  leaves 
in  our  breeding  cages  when  there  was  nothing  else  for  them  to  oviposit 
on,  but  we  never  found  any  indication  of  this  habit  in  the  field. 

From  our  breeding  cage  experiments  and  field  observations  we  are 

1  Insectes  de  la  Vigne,  p.  308. 


12  UNIVERSITY    OF   CALIFORNIA — EXPERIMENT  STATION. 

inclined  to  think  that  few,  if  any,  deposit  more  than  three  or  possibly 
four  clusters,  making  a  total  of  not  to  exceed  one  hundred,  or  possibly, 
one  hundred  and  twenty  eggs.  From  fifty  to  seventy-five  will  be  nearer 
the  average.  The  majority  of  the  beetles  in  our  cages  laid  but  a  single 
cluster  of  twenty  or  twenty-five,  but  those  were  under  slightly  un- 
natural conditions  where  there  was  not  a  constant  supply  of  fresh  food. 
A  number  of  females  were  dissected  to  determine  the  number  of  eggs 
in  the  ovaries,  and  these  varied  from  sixteen  to  twenty-four  well 
developed  eggs. 

The  eggs  of  a  cluster  are  very  slightly  glued  together  with  a  sticky 
material.  By  careful  handling  it  is  possible  sometimes  to  take  these  off 
en  masse,  but  the  majority  of  clusters  will  fall  apart  upon  the  slightest 
handling.  The  eggs  of  the  eastern  species  are  said  to  be  covered  with 
a  gummy  material  which  holds  the  entire  mass  securely  together,  but 

with  this  species  we  failed  to 
find  any  that  would  withstand 
any  very  rough  handling  or 
which  could  be  blown  off  the 
vine  in  clusters  by  the  wind. 

Time  Required  to  Hatch. — In 
our  breeding  cages  the  shortest 
time  required  to  hatch  was  eight 
days,  and  the  longest  period 
twelve  days.  This  was  under 
conditions  which  varied  but  little 

Fig.  7.    Larva  of  the  California  grape  root-  from    that    of    the    vineyard,    the 

worm,  as  it  appears  in  the  soil  (enlarged).  ,  .  i     •  -,  •£    ■ 

temperature  being  lower,  it  in 
any  way  different,  especially  in  the  forenoon,  since  the  laboratory  had 
a  west  exposure  away  from  the  morning  sun.  A  large  number  of  eggs 
were  thus  timed  for  the  incubation  period  and  they  all  came  within 
the  limits  stated  above.  This,  of  course,  may  vary  in  warmer. or  colder 
weather,  but  from  ten  to  twelve  days  may  be  taken  as  the  average 
hatching  period.  The  eggs  of  the  same  cluster  were  all  observed  to 
hatch  within  one  day. 

The  Larva. — The  young  larva  upon  hatching  from  the  egg  makes 
its  way  to  the  ground  almost  immediately.  It  may  crawl  to  the 
ground,  as  we  infer  from  finding  them  pretty  well  scattered  down 
the  trunk  of  the  vine,  or  they  may  possibly  in  many  cases  simply  drop 
to  the  ground,  though  this  was  not  actually  observed.  This  seems  to  be 
a  common  habit  with  the  eastern  species,  but  here  in  California  with 
the  short-pruned  vines,  and  consequent  nearness  to  the  ground,  we 
believe  that  most  of  the  larvge  crawl  down  the  trunk.  Young  larvaB 
kept  ander  observation  in  a  test  tube  filled  with  compacted  soil,  wan- 


Bulletin  195. 


CALIFORNIA   GRAPE   ROOT-WORM. 


13 


dered  about  looking  for  a  suitable  place  for  entering  the  earth  three 
or  four  hours  before  they  actually  disappeared.  By  the  following 
morning  they  had  gone  about  halfway  down  the  tube,  or  three  inches, 


Fig.  8.    Root  of  a  vine  with  bark  eaten  off  by  root-worm. 

and  before  the  end  of  the  same  day  they  had  burrowed  through  the  six 
inches  of  soil  in  the  tube. 

As  soon  as  the  larvae  reach  the  roots  of  the  vine  they  begin  feed- 
ing, and  it  is  generally  the  smaller  rootlets  that  are  first  attacked, 


Stem  leaf  and  fruit  eaten  by  root  beetle. 


although  we  have  found  young  larvae  around  roots  of  considerable  size. 
These  smaller  roots  may  be  eaten  off  entirely.  The  larger  roots  are 
injured  by  the  larvae  gouging  out  long  strips  of  the  bark,  which  some- 
times take  almost  any  direction,  but  on  the  roots  of  medium  size  these 


14  UNIVERSITY    OV   CALIFORNIA— -EXPERIMENT   STATION. 

strips  are  usually  oaten  out  in  a  direction  parallel  with  the  axis  of  the 
root,  or  in  a  spiral  direction.  The  "frass"  or  eaten  bark  is  left  in  their 
paths  and  is  characteristic  of  their  injury.  The  furrows  made  are  from 
one  tenth  to  one  fifth  of  an  inch  wide,  and  in  cases  of  severe  injury 
all  the  bark  may  be  eaten  away  from  the  roots. 

This  feeding  is  continued  from  the  time  they  hatch  in  the  spring 
until  the  vine  becomes  dormant  in  the  fall.  By  September  1st  some 
of  the  larvae  were  found  nearly  full  grown,  while  others  were  not  more 


Fig.  10.     Grape  leaf  showing  characteristic  work  of  the  beetle. 

than  half  grown.  In  the  case  of  the  latter,  their  growth  is  completed 
by  feeding  during  the  following  spring,  which  accounts  for  some  of  the 
larva-  being  found  as  late  as  the  last  of  May.  The  first  observed  appear- 
ance of  the  young  larvae  in  the  Lodi  section  in  1907  was  on  May  30th, 
this  being  about  a  month  after  the  first  appearance  of  the  beetles. 

The  Ihvvvt  were  found  as  far  down  as  two  and  a  half  feet,  and  no 
doubt  go  farther  than  this,  since  in  some  of  the  vines  there  were  no 
roots  to  speak  of  nea n*r  than  a  couple  of  feet  from  the  surface.  The 
larvae  wrere  found  within  a  radius  of  fifteen  inches  from  the  main  central 
root,  and  no  doubl  the  majority  occur  within  a  radius  of  a  couple  of 


Bulletin  195. 


CALIFORNIA   GRAPE    ROOT- WORM, 


15 


feet,  They  apparently  remain  dormant  during  the  winter  season, 
changing  to  pupae  the  following  spring.  Some  full  grown  larvae  of  the 
preceding  year  were  found  about  the  roots  as  late  as  May  29th  during 
1907. 

The  Pupa. — The  full  grown  larva  which  has  wintered  over  in  the 
ground  changes  to  the  pupa  in  the  early  spring.  The  larvae  upon  reach- 
ing maturity  ascend  toward  the  surface  for  pupation.  The  pupae  taken 
this  past  season  were 
found  at  a  depth  vary- 
ing from  four  to  eight 
inches  below  the  sur- 
face. The  depth  de- 
pends somewhat  upon 
the  amount  of  mois- 
ture near  the  surface. 
Those  found  nearer  the 
surface  were  taken 
from  where  there  was 
considerable  moisture 
to  within  two  or  three 
inches  from  the  sur- 
face. The  pupae,  being 
covered  with  a  delicate 
white  skin,  require  a 
fairly  moist  soil  to  pre- 
vent them  from  drying 
or  shriveling  up.  We 
met  with  this  difficulty 
of  drying  with  some  of 
the  pupae  taken  to  the 
laboratory. 

About  two  weeks  is 
required  for  the  devel- 
opment of  the  insect  in 
the  pupa  stage.  The  first  adult  beetles  seen  in  1907  and  1908  were  dis- 
covered about  May  1st,  so  that  pupation  must  have  begun  about  the 
middle  of  April.  The  insect  may,  however,  remain  in  the  pupa  stage 
for  a  month  or  more. 

The  pupa  simply  rests  in  a  little  cell  hollowed  out  by  the  larva, 
and  any  disturbance  of  the  earth  is  very  likely  to  break  this  cell  and 
expose  the  pupa,  which  on  account  of  its  delicate  structure  will  usually 
succumb  to  such  treatment. 
2— Bull.  195 


Fig. 11. 


Tip  of  a  shoot,  with  the  leaves,  stem,  petioles  and 
pedicels  attacked  by  the  root  beetle. 


L6 


UNIVERSITY   OF   CALIFORNIA — EXPERIMENT   STATION. 


/>  etle. — The  adult  beetle,  into  which  the  pupa  in  its  cell  in  the 
ground  transforms,  emerges  from  the  ground  and  begins  to  attack  the 
growing  parts  of  the  vine  above  ground.  For  the  greater  part  of  the 
season  the  insect  has  been  a  root  feeder,  but  having  completed  its  early 
stages  underground,  it  comes  to  the  surface  to  feed  for  a  brief  time, 
to  lay  its  eggs,  and  then  dies.  The  beetle  as  it  comes  from  the  ground 
is  somewhat  lighter  in  color,  but  upon  exposure  to  sun  and  light  its 

chitinous  covering 
soon  becomes  darker 
in  color  and  more 
rigid  in  texture. 

The  time  of  ap- 
pearance of  the  first 
beetles  during  the 
years  1907  and  1908 
at  Lodi  was  May 
1st.  They  may  con- 
tinue to  emerge 
until  June  1st  and 
possibly  later,  al- 
though the  greater 
number  of  the  beetles 
came  out  in  1907 
and  1908  during 
the  first  half  of 
May.  It  has  been 
stated  that  a  few 
larvae  and  pupae 
were  taken  on  May 
29th,  which  would 
indicate  that  a  few 
belated  beetles  may 
not  appear  before 
the  middle  of  June. 
The  beetles  were  most  numerous  on  the  vines  this  season  about  the 
middle  of  May.  In  the  latter  part  of  May  they  begin  to  disappear 
and  by  the  last  of  June  are  practically  all  gone. 

The  beetles  soon  begin  their  work  on  the  vine  by  feeding  upon  the 
leaves.  They  are  nearly  always  found  on  the  upper  surface.  In  feed- 
ing they  eat  out  chain-like  strips  from  the  leaves  (Fig.  10),  these  slits 
being  about  one  twentieth  of  an  inch  wide  and  from  a  quarter  to  three 
quarters  of  an  inch  long.  Sometimes  the  framework  of  the  tissues  is 
left,  making  a  skeletonized  effect,  though  often  the  entire  substance  is 


Fig.  12.     A  cluster  of  grapes  badly  gnawed  by  the  root  beetle. 


Bulletin  195. 


CALIFORNIA   GRAPE   ROOT-WORM. 


17 


eaten  away.  This 
gives  the  leaf  a 
lace-like  effect,  the 
parts  left  in  cases 
of  bad  injury  be- 
ing held  together 
by  mere  threads. 

The  beetle  also 
gouges  out  strips 
of  the  bark  of  the 
tender  shoots  in 
the  same  manner 
as  it  works  on  the 
leaves  (Fig.  11). 
Sometimes  the 
shoot  is  thus 
gouged  out  all  the 
way  around  and 
turns  brown  in 
color.  This  loss  of 
bark  or  covering 
interferes  consid- 
erably with  the 
conveyance  of 
nourishment  to  the 
fruit  and  growing 
tip.  The  petioles 
of  the  leaf  are 
similarly  attacked, 
as  are  also  the 
pedicels  of  the 
berry ;  and  the 
pedicels  being  of  a 
small  size,  a  few 
gougings  around 
them  will  cause  the 
berry  to  dry  up. 

The  berry  itself 
does  not  escape  the 
attacks  of  this 
beetle,  and  in  July 
berries  may  be  seen 
that     are     cracked 


t 

* 

mkh 

t 

$ 

# 

t 

t 

f 

Fig.  13.     The  work  of  the  beetle  on  the  berries. 


Fig.  14.     A  vine  stunted  in  growth  through  injury  to  the  roots  by 
the  California  grape  root-worm.    Photographed  June  6,  1907. 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 

open  or  gouged  out  on  one  side  (Figs.  12,  13),  and  the  growth  inter- 
fered with  as  a  resull  of  an  attack  of  these  beetles  in  May  or  June. 
The  beetles  may  continue  to  feed  for  a  month  or  more.  After  feeding 
a  couple  oi'  weeks  egg  laying  begins,  and  this  takes  place  at  intervals 
a  week  or  two.  when  the  clusters  of  eggs  are  deposited  as  already 
indicated. 

The  beetles  are  very  easily  jarred  from  the  vine  upon  the  slightest 
disturbance,  and  fall  to  the  ground  "playing  'possum"  and  remain 
quiet  for  a  short  time,  but  soon  become  active  again  when  left  undis- 
turbed. This  habit  of  readily  dropping  to  the  ground  offers  a  means 
of  controlling  the  insect  in  this  stage.  The  beetles  fly  around  but 
little,  and  will  usually  be  found  in  the  immediate  vicinity  in  which 
they  emerged.  The  vineyards  which  were  under  observation  showed 
that  the  great  bulk  of  the  beetles  were  confined  to  a  comparatively  small 
area,  and  reports  from  the  owners  indicated  that  they  had  been  present 
in  these  spots  for  several  years. 

In  the  case  of  some  vineyards,  according  to  statements  made  by  the 
owners,  these  beetles  have  been  present  for  a  good  many  years.  In 
such  cases  as  these  there  seems  to  have  been  some  factor  in  keeping 
them  from  becoming  excessive  and  destroying  the  vines.  In  one  vine- 
yard near  Lodi,  where  the  beetles  are  said  to  have  been  present  for 
many  years,  they  have  become  especially  abundant  only  during  the 
last  year  or  two.  During  this  period  they  have  also  spread  more 
rapidly,  and  since  it  has  become  known  that  they  feed  upon  the  roots 
as  well  as  the  leaves  the  growers  have  begun  to  realize  their  importance, 
and  remedial  measures  will  be  undertaken  against  the  insects. 

CONTROL  MEASURES. 

Natural. — Probably  the  most  important  factor  in  the  way  of  climatic 
control  of  this  insect  would  be  unusual  rainfall  during  the  wrinter 
season.  During  the  winter  of  1907,  which  was  a  very  exceptional 
one,  large  areas  were  covered  with  water  which,  hitherto  were  unknown 
to  have  been  flooded.  Where  this  exceptional  amount  of  moisture  pre- 
vailed and  vineyards  were  covered  for  a  couple  of  weeks,  there  were 
very  few  beetles  during  the  following  season.  Except  in  one  or  two 
)8,  however,  we  were  not  aware  of  the  fact  that  beetles  had  occurred 
in  those  situations  in  previous  years.  But  they  were,  nevertheless, 
present  again  in  1908. 

Aside  \'v<)in  r-xcessive  moisture  in  the  soil,  there  is  little  in  the  way 

of  climatic  control  that  will  aid  in  the  fight  against  the  insect,  unless  it 

lid  be  in  some  eondition  that  would  be  conducive  to  the  development 

fungus   affecting   the   adult  beetle.     In  our   interior   California 

ther,  however,  of  May  and  June  there  is  little  hope  of  anything 


Bulletin  195.  CALIFORNIA  GRAPE  ROOT-WORM.  19 

very  effective  appearing  as  dependent  primarily  upon  moist  weather. 
The  fact  that  the  eggs  of  this  beetle  are  very  securely  hidden  away 
beneath  one  or  more  layers  of  bark  affords  little  opportunity  for  them 
to  be  attacked  in  any  large  manner  by  parasitic  or  predatory  insects. 
The  young  larva  is  for  a  brief  period  (from  the  time  of  hatching  until 
it  enters  the  ground)  more  or  less  exposed  to  the  attacks  of  enemies, 
but  the  interval  is  generally  too  short  to  allow  of  very  great  destruction. 
Once  in  the  ground — where  it  remains  for  the  greater  part  of  the  year — 
it  is  pretty  safe  from  most  enemies.  About  the  only  thing  likely  to 
attack  the  larva  here  would  be  the  predaceous  ground  beetles.  None 
of  these  were  actually  observed  attacking  them  during  the  past  two 
years.  The  larva  is  usually  so  deep  in  the  ground  as  to  be  out  of  reach 
of  most  natural  enemies. 

The  pupa  comes  nearer  to  the  surface  and  is  hence  more  liable  to 
attack.  It  is  probably  in  this  stage  that  the  greatest  mortality  occurs, 
both  from  enemies  and  from  cultivation  of  the  soil  and  other  opera- 
tions by  man.  In  the  adult  or  beetle  stage,  the  insect  is  directly  exposed 
and  is  likely  to  be  attacked  by  a  large  number  of  enemies,  including 
insects  and  birds. 

ARTIFICIAL    CONTROL. 

Of  the  Egg. — Since  the  eggs  are  secreted  under  one  or  more  layers 
of  bark,  there  is  little  possibility  of  any  spray  or  wash  reaching  them. 
On  account  of  their  small  size  and  the  difficulty  of  finding  the  clus- 
ters, hand  picking  is  out  of  the  question.  Those  who  believe  in 
stripping  off  the  old  bark  and  spraying  with  bluestone  during  the 
dormant  season,  with  the  primary  object  of  preventing  black  knot, 
will,  incidentally,  inconvenience  these  beetles  by  doing  away  with 
the  more  favorable  situations  for  egg  laying.  This,  however,  can 
not  be  counted  upon  as  very  effective  in  controlling  the  beetle.  The 
eggs  will  be  deposited  in  spite  of  this  treatment,  and  freeing  the  vines 
from  their  loose  bark  will  result  simply  in  rendering  the  eggs  a  little 
more  exposed  to  the  attack  of  enemies. 

Of  the  Larva. — The  matter  of  controlling  any  underground  insect 
is  a  difficult  problem,  and  the  larva  of  this  beetle  is  no  exception  to 
the  general  rule.  Various  remedies  and  schemes  have  been  tested  for 
accomplishing  this  work,  but  the  greater  number  of  them  have  been 
abandoned.  The  problem,  therefore,  is  now  limited  largely  to  control 
by  resistant  stock,  cultivation,  crop  rotation,  or  other  regular  farm 
practices;  but,  with  an  insect  such  as  this,  that  spends  a  portion  of 
its  existence  above  ground,  it  is  not  necessary  to  control  it  in  the  larval 
stage,  since  it  can  be  more  easily  and  effectively  done  in  a  later  stage. 

It  was  suggested  by  some  of  the  growers  that  something  might  be 


20  UNIVERSITY   OF   CALIFORNIA EXPERIMENT    STATION. 

applied  to  the  ground  to  prevent  the  larvae  from  entering,  but  knowing 
the  results  of  the  New  York  experiments1  along  this  line,  we  gave 
little  encouragement  to  the  idea,  and  did  not  repeat  the  experiments. 
Kerosene  emulsion  and  crude  petroleum  were  used  in  New  York,  but 
neither  proved  of  any  practical  value.  The  trouble  with  such  sub- 
stances is  that  they  are  too  readily  absorbed  by  the  dry  soil  and  too 
quickly  evaporated.  Our  California  crude  oil,  which  has  an  asphaltum 
base  (instead  of  paraffine,  as  is  the  case  with  eastern  oils),. would  not 
disappear  so  quickly,  but  few  farmers  would  want  such  a  substance 
mixed  with  their  soil. 


"Ci 

:'/-"J'..^V^,-:':^..'     ' 

fife. ' 

■■• 

Vfm^^WtJ^m 

J&M^W1P| 

5§?i 

i     muSSm 

^&£\    ;     _  '•-"  ". 

1L_J 

•  jj^*"' , 

'•".- 

\          .  :-mSm 

Fig.  15.     At  work  digging  out  larvae  of  the  California  grape  root-worm'two 
and  one  half  feet  beneath  the  surface. 

Of  the  Pupa. — As  heretofore  stated,  the  pupae  are  found  at  a  depth 
of  from  four  to  eight  inches  below  the  surface.  This,  together  with 
the  fact  that  any  disturbance  of  the  cell  in  which  they  are  resting  will 
generally  prove  fatal,  offers  a  chance  of  doing  something  in  the  way  of 
control  while  in  this  stage.  While  some  of  them  are  beyond  the  depth 
of  the  plow  as  ordinarily  used  about  the  vine,  yet  probably  the  major- 
ity will  be  found  within  about  six  inches  from  the  surface.  They  do 
not  come  up  to  the  dry  soil  to  pupate,  but  remain  just  below  it.  If 
a  shallow  mulch  of  two  or  three  inches  can  be  kept  immediately  around 
the  vines  until  the  insects  are  ready  to  pupate,  this  will  conserve  the 

1  \(-w   Vr.rk    Sfufp   Afimfiim    "P.nllftin   HO.   n.    77. 


Bulletin  195. 


CALIFORNIA   GRAPE   ROOT-WORM. 


21 


moisture  just  below  the  mulch  and  encourage  the  larvae  to  come  nearer 
the  surface  to  transform  to  the  pupae.  If  then,  at  the  proper  time, 
just  before  the  beetles  begin  to  emerge,  the  soil  about  the  vine  is  stirred 
to  a  depth  of  about  six  inches,  no  doubt  a  large  percentage  of  them 
will  be  destroyed.  Another  point,  and  one  which  makes  the  problem 
more  difficult,  is  that  the  pupae  do  not  all  appear  at  once,  but  may  be 
found  for  a  month  or  more.  This  may  make  it  necessary  to  go  over  the 
ground  more  than  once.  However,  probably  the  majority  of  the  beetles 
emerge  at  about  the  same  time  in  the  early  part  of  the  season,  and,  if 
measures  are  taken  against  the  pupae  just  preceding  the  emergence, 
large  numbers  of  them  will  be  destroyed.    If  more  than  one  cultivation 


.-  y 

iwl 

"VIM                                       / 

-:C^->jJv^;"'-'«:  ::-tr  •.   ~^ 

Fig.  16.      Vines  enclosed  with  mosquito  netting  to  determine  if  beetles  will  emerge  through 

uncultivated  soil. 

is  undertaken  they  should  be  done  at  intervals  not  to  exceed  two  weeks, 
since  the  pupae  will  complete  their  development  within  this  period. 

This  matter  of  deep  cultivation  for  two  or  three  feet  around  the 
vine,  while  not  expected  to  completely  control  the  insect,  will,  never- 
theless, aid  in  its  control.  It  is,  of  course,  of  no  use  unless  done 
at  the  proper  time — when  the  insect  is  in  the  pupal  stage.  The 
proper  time  for  such  cultivation  during  the  past  two  years  at  Lodi 
would  have  been  during  the  last  of  April,  but  this  may  vary  with  the 
season  and  locality. 

It  is  possible  that  in  some  soils  the  destruction  of  the  beetles  before 
they  emerge  from  the  ground  may  be  accomplished  in  another  way. 
In  making  some  experiments  at  Florin,  in  1905,  for  the  determination 
of  the  causes  of  the  sunburn  of  Tokay  grapes,  Mr.  B.  J.  Wingfield 


UNIVERSITY    OF   CALIFORNIA EXPERIMENT   STATION. 


round  that  the  beetles  were  unable  to  force  their  way  out  of  the  ground 
when  it  was  covered  with  a  hard,  uncultivated  crust,  such  as  is  left 
after  rain  on  clayey  soils.  Each  of  six  vines  was  covered  on  May  4th 
with  a  cage  of  mosquito  netting.  In  three  of  these  cases  the  netting 
was  tied  tightly  around  the  lower  part  of  the  stem,  as  shown  in  figure  16, 
in  order  to  prevent  the  possibility  of  any  beetles  getting  on  to  the 
above-ground  portion  of  the  vine.     In  the  other  three  cases  the  netting 

was  brought  down 


Fig.  IT.      A  single  vine  as  shown  in  figure  10. 


to  the  ground, 
enclosing  about 
three  square  feet 
of  soil  surface  in- 
side the  cage,  as 
also  .  shown  in 
figure  16.  This 
enclosed  surface 
remained  unculti- 
vated until  about 
the  middle  of 
July,  when  the 
cages  were  re- 
moved. 

Xo  beetles  were 
found  at  any  time 
on  any  of  the 
six  enclosed  vines, 
and  no  signs  of 
their  attacks  on 
leaves,  fruit  or 
other  above- 
ground  portions. 
This  is  easily  ex- 
plained in  the 
case  of  the  vines 
which  were  com- 


pletely  shielded  from  attack  by  tying  the  netting  around  the  stump; 
but  in  t}i<-  case  of  the  other  vines  which  were  exposed  to  any  beetles 
which  might  emerge  from  the  soil  within  eighteen  inches  from  the 
stump,  the  only  explanation  seems  to  be  that  the  beetles  were  unable  to 
force  their  way  through  the  compacted  surface  crust.  That  the  pupa? 
and  beetles  were  abundant  in  the  ground  was  shown  by  the  fact  that 
>:]]  the  uncovered  vines  next  to  those  which  were  covered  were  badly 
sted  by  the  beetles  and  showed  abundant  evidences  of  their  attack 
on  aJi  parts. 


Bulletin  195.  CALIFORNIA  GRAPE  ROOT-WORM.  23 

The  effectiveness  of  a  method  based  on  this  experiment  would  depend 
largely  on  the  type  of  soil.  Only  a  soil  that  will  form  a  hard,  com- 
pact surface  layer  could  be  utilized  according  to  this  plan. 

We  do  not  know  how  it  would  appeal  to  the  growers  to  leave  three 
or  four  feet  about  the  vine  uncultivated  until  about  the  middle  of  May 
or  possibly  later,  as  would  be  necessary  in  this  case ;  but  if  the  beetles 
were  present  in  large  numbers  and  this  controlled  them,  it  would  pay 
amply.  Again,  showers  of  rain  that  are  apt  to  come  as  late  as  the  mid- 
dle of  May  would  soften  the  soil  and  militate  against  the  method. 

Spraying. — The  adult  or  beetle  eats  away  portions  of  the  leaf  or 
gouges  out  strips  of  the  surface  of  the  shoots  and  other  growing  parts, 
so  that  a  poison  applied  to  the  vine  will  be  consumed  by  it  in  this  opera- 
tion. The  most  serious  drawback  to  poisoning  is  the  fact  that  beetles 
are  pretty  resistant  to  poisons,  and  considerable  amounts  must  be  con- 
sumed before  the  insects  are  killed.  However,  if  a  strong  arsenical 
spray  is  thoroughly  applied  at  the  beginning  of  the  attack  it  will 
prove  to  be  fairly  successful. 

In  the  experiments  this  season  the  beetles  were  killed  in  from  two  to 
three  days  on  leaves  thoroughly  sprayed  with  lead  arsenate  in  the 
ratio  of  five  pounds  to  fifty  gallons  of  water.  One  pound  of  paris 
green  to  seventy-five  gallons  of  water  also  gave  good  results.  In  the 
case  of  paris  green  a  few  vines  should  be  used  as  a  test  to  determine 
the  maximum  amount  that  is  safe  for  the  foliage,  since  there  is  danger 
of  burning  if  used  too  strong. 

It  is  not  a  very  difficult  matter  to  spray  the  short-pruned  California 
vine  during  the  last  of  April  or  the  first  of  May,  and  thorough  work 
can  be  done  at  this  time.  The  spray  should  be  applied  mostly  from 
above,  since  it  is  on  the  upper  surface  of  the  leaves  and  shoots  that  most 
of  the  feeding  is  done. 

Jarring. — Since  the  beetle  is  very  readily  jarred  from  the  vine,  this 
offers  one  of  the  most  satisfactory  means  of  controlling  the  insect. 
Generally  it  is  only  those  that  are  in  a  cup-shaped  leaf,  or  in  a  grape 
cluster,  or  in  some  part  of  the  old  wood,  that  will  not  be  disturbed  by 
a  reasonable  jarring. 

This  method  has  the  advantage  of  killing  the  beetles  directly,  before 
egg  laying  is  commenced,  which  may  not  always  be  done  by  means  of 
the  poison  spray.  The  worst  objection  to  the  method  is  that  the  beetles 
may  keep  emerging  from  the  ground  for  three  or  four  weeks,  making 
more  than  one  treatment  necessary.  Fortunately,  however,  these 
attacks  are  generally  confined  to  a  limited  portion  of  the  vineyard,  so 
that  the  problem  is  not  so  difficult  as  it  would  be  were  it  necessary  to 
go  over  the  entire  area. 


24 


UNIVERSITY   OF   CALIFORNIA EXPERIMENT   STATION. 


The  sort  of  apparatus  which  was  used  successfully  on  a  badly  in- 
fested vineyard  near  Lodi  this  year  was  the  vine-hopper  cage  shown  in 
figure  IS.  This  device  was  constructed  for  capturing  the  vine  hopper, 
and  when  a  nearby  vineyard  became  infested  with  the  beetles  it  was 
used  against  them. 

This  cage  consists  of  an  ordinary  mosquito  netting  tacked  over  a 
square  framework  of  laths  or  some  other  light  material.  The  essential 
part  of  it  so  far  as  the  beetles  are  concerned  is  the  tray  at  the  bottom. 
This  is  made  of  a  sheet  of  galvanized  iron  turned  up  about  an  inch  at 

the  edges.  The 
crude  oil  which 
is  placed  in  this 
tray  is  fatal  to 
all  insects  falling 
into  it. 

The  V-shaped 
opening  in  the 
tray  permits  the 
cage  to  be  pushed 
on  to  the  vine, 
which  is  bumped 
at  the  same  time 
and  the  beetles 
jarred  off.  A  pad- 
ding of  leather 
is  tacked  on  the 
base  of  the  open- 
ing in  front  of 
the  vine.  The 
opening  may  be 
closed  by  tacking 
two  strips  of  can- 
vas, one  on  each  side,  so  as  to  meet  in  the  center.  These  strips  are  sup- 
ported by  transverse  pieces  of  three-quarter  inch  rubber  tubing,  which 
are  sewed  on  to  the  canvas  beneath.  This  rubber  tubing  supports  the 
canvas  over  the  opening,  and  when  the  cages  are  placed  in  position  it 
fives  way  for  the  base  of  the  vine,  but  immediately  springs  back  again 
through  the  flexibility  of  the  rubber.  Steel  strips  will  answer  the  same 
purpose,  but  the  rubber  is  described  because  it  is  cheaper  and  more 
easily  obtained. 

This  cage  has  the  advantage  of  catching  the  vine  hopper,  which  is 
likely  to  be  present,  with  the  same  operation.  For  the  beetle  alone, 
simply  the  tray  at  the  bottom  may  be  used,  or  the  sides  extended  up 


-.     A  cage  used  to  capture  the  beetles  on  the  vine. 


Bulletin  195.  CALIFORNIA  GRAPE  ROOT-WORM.  25 

and  slightly  outward  with  wire  netting  or  canvas,  to  get  those  that  may 
be  on  the  outer  parts  of  the  vine.  Handles  may  be  attached  to  this, 
so  that  it  can  be  manipulated  without  stooping.  Such  a  cage  can  go 
over  four  or  five  acres  a  day,  and  there  is  little  outlay  save  the  time  of 
the  men  doing  the  work.  Since  the  beetles,  if  taken  in  time,  are  dis- 
tributed over  a  comparatively  small  portion  of  the  vineyard,  it  means 
but  a  day's  work  or  two.  This,  then,  can  be  repeated  three  or  four 
times,  if  necessary,  without  much  expense,  and  the  vines  saved  from 
imy  further  ravages  of  the  pest. 

SUMMARY. 

This  insect  has  been  a  destructive  enemy  of  the  vine  in  Europe 
for  many  years,  and  for  several  years  past  it  has  been  doing  considerable 
damage  to  the  grape  in  California.  A  related  native  species  is  an 
important  pest  of  the  vines  in  the  East. 

It  attacks  both  the  roots  and  the  growing  parts  of  the  vine  above 
ground.  From  June  to  May  the  insect  is  in  its  larval  and  pupal  stages 
underground.  During  May  and  June  it  works  on  the  parts  of  the 
vine  above  ground  as  a  beetle. 

Many  of  the  pupas  may  be  destroyed  by  deep  cultivation  for  a  radius 
of  two  or  three  feet  about  the  base  of  the  vine. 

The  beetles  may  be  killed  by  a  strong  arsenical  spray,  or  by  jarring 
into  crude  oil,  or  otherwise  captured  as  they  are  shaken  from  the  vine. 


PUBLICATIONS. 

BIBLIOGRAPHY. 

LH02.  Aldrovandi,  De  Insoctes. 

1732.  Pluehi,   Spectacle  de  nature,  Paris. 

1764.  Geoffrey,    Histoire  abregee  des*  Insectes  des   environs  de  Paris. 

1S04.  Latrielle,    Histoire    naturelle    g6n6rale    et    particuliere    des    Crustaces    et    des 

Insectes   (Paris  Hist.  Ins.  1804,  11.  p.  331). 

L819.  Latrielle.    Nouveau   Diet.  d'Histoire   Nat. 

1S28.  Touchey,  Bull.  Soc.  Agr.,  Herault,  p.  5. 

-   •  Wostwood.  J.  O.     Westwood  on  Insects,  vi,  p.  247. 

l^r>.  Walckener,  Ann.  de  la  Soc.  Ent.  de  Fr.,  iv,  p.  687  et  seq. 

1841.  Vallot,  Histoire  des  Insectes  Ennemies  de  la  Vigne. 

1842.  Audouin.   Insectes  Ennemies  de  la  Vigne. 

1S46.  Guerin-Meneville,  Ann.  Soc.  Ent.  Fr.,  1840,  Ser.  2.  T.  4,  Bull.  p.  35. 

1 849.  Deinermety.  Quelques  faits  sur  l'Ecrivain,  Jour.  d'Agr.  de  Dijon. 

1S62.  Guerin-Meneville.  Rev.  Mag.  Zool.,  14,  pp.  360-4. 

1S64.  Baron  Thenard.  Comtes  Rendus  Acad.  Sci.,  6  Novembre,  Vinas,  Le  Gribouri 

(Revue  viticole  de  Dijon). 

1S73.  Horvath.    Beitrag   zur    Naturgeschicte    von    Emolpus   vitis,    Ann.    de    la    Soc. 

Imp.  Roy.  Zool.  Bot.  de  Vienne. 

1874.  Lichenstein,  Ann.  Soc.  Ent.  Fr.,  Ser.  5,  T.  iv,  Bull.  p.  228. 

1874.  Girard,  Maurice,  Ann.  Soc.  Ent.  Fr.,  Ser.  — ,  T.  iv,  Bull.  pp.  63  et  140. 

1S76.  Lichenstein,  Ann.  Soc.  Ent.  Fr.,  Ser.  5,  T.  v,  Bull.  p.  105. 

1S76.  Arviset,  Bull.  Insectol  Agric,  Paris,  T.  i,  p.  182. 

1876.  Rendu,  V.,  Les  Insectes  Nuisibles  A  1' Agriculture,  pp.  106-107. 

1S76.  Perris,  Ann.  Fr.,  vol.  6,  pp.  216-217. 

1S7S.  Valery    Mayet    et    Lichtenstein,    Etude    sur    le    Gribouri,    Ann.    Societe    des 

Agr.    de    France    and   Ann.    Societe    d'Horticulture    et    d'Histoire    nat.    de 

l'Herault. 

1879.  Lichenstein,  Etudes  sur  le  Gribouri  ou  ecrivain  de  la  Vigne,  Montpellier,  p.  12. 

1880.  Pacific  Rural  Press,  May  29. 

1SS1.  Jobert,  C.  R.,  Acad.  Sci.,  Paris,  T.  93,  pp.  975-7,  Jour.  R.  Microsc,  Ser.  2, 

vol.  ii.  pp.  1-39. 

1S82.  Cooke,  Matthew,  Injurious  Insects  of  the  Orchard  and  Vineyard,  p.  194. 

1883.  Kittel,  Correspbl.  Zool.  Min.  Ver.,  Regensburg,  37,  p.  157. 

1887.  Andre,  Metamorphosis  de  l'Eumolpus  vitis.     Le  Naturaliste,  Paris,  pp.  96-98. 

1887.  Oliver,  E.,  Ann.  Soc.  Ent.  Fr.  1887,  Ser.  vi,  T.  7,  p.  128. 

1889.  Le  Progres  Agricole,  x.  No.  37,  pp.  576-S, 

1890.  Mayet,  Les  Insectes  de  la  Vigne,  p.  321. 

1890.  Ricksecker.  L.  E.,  Orchard  and  Farm,  June,  p.  59. 

1891.  Montillot,  Louis,  Les  Insectes  Nuisibles,  pp.  114-6. 
1891.  Craw,  Alexander.  Destructive  Insects. 

1891.  Riley  and  Howard,  Insect  Life,  vol.  iii,  pp.  298  and  349. 

1892.  Horn,  Dr.  Geo.,  American  Entomological  Society,  vol.  19,  p.   196. 

1893.  Rupertsburger,  Wein.  Ent.  Zeit,  xii,  p.  215. 

1896.  Sajo,  K.  Selus,  Wochenschr.  Ent.,  i.  No.  32,  p.  501. 

1897.  Sajo,  K.  Selus,  Wochenschr.  Ent,  ii,  No.  9,  pp.  129-34. 

1897.  Coste,  Floret  P.,  Progres  Agricole  et  Viticole,  Nos.  30.  32.  and  33. 

1908.  Quayle,  H.  J.,  Jour.  Ec.  Ent.,  vol.  I,  No.  3,  p.  175. 


PUBLICATIONS.  Z  i 


STATION  PUBLICATIONS  AVAILABLE  FOR  DISTRIBUTION, 


REPORTS. 


1890.     Report    of    the    Viticulrural    Work    during    the    seasons    1887-93,    with    data 

regarding  the  Vintages  of  1894-95. 
1S97.     Resistant    Vines,    their    Selection,    Adaptation,    and    Grafting.      Appendix    to 

Viticulrural   Report  for   1890. 
1898.     Partial   Report  of   Work   of  Agricultural    Experiment   Station   for   the  yearg 

189.1-90  and  1890-97. 
1900.     Report  of  the  Agricultural  Experiment  Station  for  the  year  1897-98. 

1902.  Report  of  the  Agricultural  Experiment  Station  for  1898-1901. 

1903.  Report  of  the  Agricultural  Experiment  Station  for  1901-1903. 

1904.  Twenty-second  Report  of  the  Agricultural  Experiment  Station  for  1903-1904. 

TECHNICAL  BULLETINS— ENTOMOLOGICAL  SERIES. 

Vol.  1,  No.  1 — Wing  Veins  of  Insects. 

No.  2 — Catalogue  of  the  Epkydridae. 

BULLETINS. 

Reprint.  Endurance  of  Drought  in  Soils  of  the  Arid  Region. 

No.  12S.  Nature,  Value  and  Utilization  of  Alkali   Lands,  and  Tolerance  of  Alkali. 
(Revised  and  Reprint,  1903.) 

133.  Tolerance  of  Alkali  by  Various  Cultures. 

140.  Lands  of  the  Colorado  Delta  in  Salton  Basin,  and  Supplement. 

142.  Grasshoppers  in  California. 

147.  Culture  Work  of  the  Substations. 

149.  California    Sugar   Industry. 

150.  The  Value  of  Oak  Leaves  for  Forage. 

151.  Arsenical  Insecticides. 

152.  Fumigation  Dosage. 

153.  Spraying  with  Distillates. 

154.  Sulfur  Sprays  for  Red  Spider. 
150.  Fowl  Cholera. 

158.  California   Olive  Oil:    its   Manufacture. 

159.  Contribution  to  the  Study  of  Fermentation. 

100.  The  Hop  Aphis. 

101.  Tuberculosis  in  Fowls.      (Reprint.) 

102.  Commercial  Fertilizers.      (Dec.  1,  1904.) 

103.  Pear  Scab. 

104.  Poultry  Feeding  and  Propriptary  Foods.      (Reprint.) 

105.  Asparagus  and  Asparagus  Rust  in  California. 
1(50.  Spraying  for  Scale    Insects. 

1(»7.     Manufacture  of   Dry   Wines  in   Hot  Countries. 

108.  Observations  on   Some   Vine  Diseases  in   Sonoma  County. 

109.  Tolerance  of  the  Sugar  Beet   for  Alkali. 

170.  Studies  in  Grasshopper  Control. 

171.  Commercial  Fertilizers.      (June  30.   1905.) 

172.  Further  Experience  in  Asparagus  Rust  Control. 

174.  A   New  Wine-Cooling  Machine. 

175.  Tomato  Diseases  in  California. 

170.  Sugar  Beets  in   the   San   Joaquin  Valley. 

177.  A  New  Method  of  Making  Dry  Red  Wine. 

178.  Mosquito  Control. 

179.  Commercial  Fertilizers.      (June,  1900.) 

180.  Resistant  Vineyards. 

181.  The  Selection  of  Seed- Wheat. 

182.  Analvsis  of  Paris  Green  and  Lead  Arsenate.     Proposed  Insecticide  Law. 
1S3.  The  California  Tussock-moth. 

184.  Report  of  the  Plant  Pathologist  to  July  1,  190G. 

185.  Report  of  Progress  in  Cereal  Investigations. 
180.     The  Oidium  of  the  Vine. 

187.  Commercial    Fertilizers.      (January,   1907.) 

188.  Lining  of  Ditches  and  Reservoirs  to  Prevent  Seepage  Losses. 

189.  Commercial  Fertilizers.      (June,  1907.) 

190.  The  Brown   Rot  of  the  Lemon. 

191.  California  Peach  Blight. 

192.  Insects  Injurious  to  the  Vine  jn  California. 

193.  The  Best   Wine   Grapes  for  California ;   Pruning  Young   Vines ;    Pruning 

the  Sultanina. 

194.  Commercial  Fertilizers   (Dec.  1907). 


28 


PUBLICATIONS. 


CIRCULARS. 


No.     1. 

s: 

4. 

5. 

7. 

9. 

10. 

11. 

12. 
13. 

15. 


16. 

17. 

IS. 
19. 
21. 

22. 

23. 
24. 
25. 


Texas  Fever. 

Blackleg. 

Hog  Cholera. 

Anthrax. 

Contagious  Abortion  in  Cows. 

Remedies  for  Insects. 

Asparagus  Rust. 

Heading  Course  in  Economic 
Entomology.      (Revision.) 

Fumigation  Practice. 

Silk  Culture. 

The  Culture  of  the  Sugar  Beet 

Recent  Problems  in  Agriculture. 
What  a  University  Farm  is 
for. 

Notes  on  Seed-Wheat. 

Why  Agriculture  Should  be 
Taught  in  the  Public  Schools. 

Caterpillars  on  Oaks. 

Disinfection  of  Stables. 

The  Advancement  of  Agricul- 
tural Education. 

Defecation  of  Must  for  White 
Wine. 

Pure  Yeast  in  Wineries. 

Olive  Pickling. 

Suggestions  Regarding  Exam- 
ination of  Lands. 


No.  2G. 
27. 


28. 


29. 


30. 
31. 


32. 
33. 

34. 


35. 


36. 


Selection  and  Preparation  of 
Vine  Cuttings. 

Marly  Subsoils  and  the  Chlo- 
rosis or  Yellowing  of  Citrus 
Trees. 

A  Preliminary  Progress  Report 
of  Cereal  Investigations, 
1905-07. 

Preliminary  Announcement  Con- 
cerning Instruction  in  Prac- 
tical Agriculture  upon  the 
University  Farm,  Davisville, 
California. 

White  Fly  in  California. 

The  Agricultural  College  and  Its 
Relationship  to  the  Scheme  of 
National    Education. 

White  Fly  Eradication. 

Packing  Prunes  in  Cans.  Cane 
Sugar  vs.  Beet  Sugar. 

California  State  Farmers'  In- 
stitute at  the  University 
Farm. 

Southern  California  Patholog- 
ical Laboratory  and  Citrus 
Experiment  Station. 

Analyses  of  Fertilizers  for  Con- 


Copies  may  be  had  on  application  to  Directob  of  Experiment  Station,  Berkeley,  Cal. 


